The present invention relates to a method for producing a result and a device to implement this method.
In certain systems such as devices used in aircraft comprising several machines, instruments, sensors and the like that transmit and/or receive optical or electrical signals, these signals are transmitted asynchronously, namely in a manner that is completely independent with respect to one another. In general, these signals travel on a bus known as an "aircraft bus". In order to avoid overlapping of these signals on the bus, a standardized transmission protocol (ARINC 629) controls the timing of transmission from the devices having information to be sent. Each of these devices generally comprises counting and sequencing units, whose pace is set by an external clock. These units receive signals representing various mutually independent external events (signals from sensors, commands, etc.). The sequencer implements an algorithm which, on the basis of different external events and information elements generated by the counting unit, prepares a single result signal representing for example a command or authorization for transmission on the bus to one or more other devices. The various devices have to generate, each in turn, their result signal to prevent any overlapping of information on the bus: this is the task of the ARINC 629 transmission. However, it may happen that, as a result of drifts in the components of the counters and sequencers, the resultant signals from the devices are transmitted outside the temporal windows that are assigned to them. To avoid the detrimental consequences of such phenomena, it is possible to widen the temporal windows. This is not appropriate in certain applications. It is also possible to choose components with reduced drift, but this substantially increases the cost of the devices.